Compact heat exchange component



United States Patent [72] Inventor Charles 0. Kunz East Alton, Illinois2: Appl. No. 741,982

[22] Filed July 2,1968 [4-5] Patented Nov. 3, 1970 [73] Assignee OlinCorporation a corporation of Virginia [54] COMPACT HEAT EXCHANGECOMPONENT 6 Claims, 8 Drawing Figs.

[52] 11.8. C1. 165/181, 29/1573 [51] int. Cl; F281 1/14 [50] Field ofSearch 165/181(MF), 181(1F), 181

v [56] References Cited UNITED STATES PATENTS 3,206,838 9/1965 Pauls165/181X hi I, l ll 1 l. I I i 2,868,515 1/1959 Garland 165/1503,294,162 12/1966 Loeh1einetal.... 165/181 3,343,596 9/1967 Kritzer165/183X 3,151,670 10/1964 Kritzer 165/181X 3,360,040 12/1967 Kritzer165/181 3,404,446 10/1968 Kritzer 165/18l-X ABSTRACT: A heat exchangecomponent is provided which is made of at least two sheets of metaljoined together at ap propriate portions thereof to define a cavitythrough which a cooling medium is passed. Edgeportions of the sheets,however, are not joined and are bent apart and twisted in a manner toobtain optimum surface area for a given volume into which such a heatexchanger would be placed.

Patented Nov. 3, 1970 Shut 1 012 Ow MU k mM H m m ATTORNEY Patented Nov.3, 1970 3,537,516

Sheet 2 M2 1 lA/Hlllllllllllllllllf &1111111111111111111111 ja/ 111111111/1 1 T 1111111)11111f INVENTOR CHARLES 0 KUNZ ATTOR EY COMPACT HEATEXCHANGE COMPONENT As described in application Ser. No. 630,376, filedApr. 12, 1967, now abandoned, assigned to the same assignee as thepresent invention, heat exchange components and a method of forming heatexchange components are described in which at least two sheets ofmaterial are bonded together at appropriate portions thereof, so as todefine at least one cavity through which a heat exchange medium ispassed. However, the edge portions are not bonded together; rather, theedge portions are bent apart to define heat exchange fin area. Forexample, a heat exchange medium to be cooled may be passed over the finsand because of the large surface area presented by the fin area, veryeffective heat exchange is achieved between the fluid passing over thefins and a heat exchange medium passing through the conduit.

While heat exchangers of this type have been found to be very effectivefor many applications, where the space for a heat exchanger must be keptto a minimum, the problem is presented of how to utilize the fin arearesulting from bending the edge portions of the sheet apart so as toobtain the most efficient use of a given volume available for heatexchange.

It is, therefore, an object of the present invention to obtain maximumheat exchange for a given volume available for heat exchange.

It is another object of the present invention to provide the maximumamount of fin surface area for a given volume available for heatexchange.

It is another object of the present invention to provide a heatexchanger in which very effective heat exchange is achieved between aheat exchange medium passing over the fin area and a cooling mediumpassing through at least one conduit which is integral with said finarea.

Other objects .will appear from the following description and drawings,in which:

FIG. 1 is a top view showing a stop-weld pattern which may be applied toone of the sheets to be used in forming the heat exchanger of thepresent invention;

FIG. 2 is a top view of a partially completed heat exchanger which showsthe edge portion fin area cut to define fin area;

FIG. 3 is a perspective view of a portion of a heat exchanger accordingto the present invention with the individual fins being bent andtwistedso as to minimize the space required for a given amount of heatexchange;

FIG. 3A is a modification of FIG. 3;

FIG. 4 is a perspective view of a helically wound heat exchangeraccording to the present invention;

FIG. 5 is a top view of a helically wound heat exchanger according tothe present invention;

FIG. 6 is a side view of a heat exchanger according to the presentinvention which has been wound in a serpentine shape and tiered; and

FIG. 7 is a bottom view of a heat exchanger according to the presentinvention which has been wound in the form of a serpentine and tiered.

The heat exchanger of the present invention is shown most clearly inFIG. 3. A heat exchanger 10 having a conduit portion is provided betweenbonded areas 30 and 31.

Individual fins 40 are provided. The fins 40 are integral with thebonded areas 30 and 31. The fins 40 comprise an edge portion 41 which isrelatively flat and is generally perpendicular to a plane passingthrough bonded portions 30 and 31. The fins also have a base portion 42which is integral with either bonded portion 30 or 31. At the baseportion, the fins have been bent approximately 90, apart with respect tothe plane passing trough bonded portions 30 and 31. Additionally, thefins have been twisted approximately 90. Thus, the fin edge portion 41is perpendicular to a plane passing through the base portions 30 and 31.

It will thus be apparent that not only are the individual fins 40 eachbent in opposite directions from each other approximately 180, but alsothey are also rotated or twisted 90 so that the faces of edge portions41 are transverse with respect to the longitudinal axis of the heatexchanger.

The heat exchanger 10, as shown in FIG. 3, contains two parallelportions 50 and 60 joined to each other and integral 5 with a bendportion 70. In the bend portion 70, it will be apparent that fin members71 and 72 on the outside of the bend section are at a greater distancefrom each other than are the fins 42 and 43 in the parallel portion.Additionally, the angle between the fin members 71 and 72, as defined bya plane passing through each of them in a vertical direction, is acutewhereas planes passing through the fins 42 and 43 would appear to nevermeet, i.e., fins 42 and 43 are approximately parallel.

Furthermore, on the inside of the bend section 70, the fins, forexample, 73 and 74, appear to be bent towards each other and would havean acute angle approximately defined by a plane passing through each ofthe fins 73 and 74. The planes would appear to approximately meet at acenter point 75, located approximately halfway between portions 50 and60.

In another embodiment of the present invention, shown in FIG. 3A, a heatexchanger 100 is shown. As was the case in FIG. 3, a center conduit 200is provided, together with bonded portions 300 and 310. Furthermore,fins 400 are provided. As was the case in FIG. 3, the edge portion 410of the fins are transverse to the longitudinal axis of the heatexchanger. The embodiment in FIG. 3A differs from that in FIG. 3 in thatthe fins 400 are bent more than 180 apart. Thus, there is an angle ofgreater than between a plane passing through the bonded portions 300 and310 and the fins 400. As was the case in FIG. 3, the fins are twisted atthe base portion 420 so that the edge portions 410 are transverse to thelongitudinal axis of the heat exchanger. This embodiment utilizes evenless space than the embodiment in FIG. 3. By careful assembly, even morefin area can be obtained for a given volume with the embodiment in FIG.3A than can be attained in the embodiment in FIG. 3.

One exemplary method of making a heat exchanger according to the presentinvention is to apply to one sheet of material 100, a pattern ofstop-weld material 101. This stop-weld pattern may comprise a centerportion 103 throughout the entire length of the strip. If desired, theend portions of the center strip 104 and 105 may be somewhat wider thanthe remainder of the strip so that a somewhat larger opening is providedat the ends for inflation and attachment of equipment used to circulatea heat exchanger through the center passageway.

The pattern may also comprise edge portions 106 and 107. These portionsoperate to avoid bonding so that the fins 40 can be provided. It willthus be apparent that two bonding strips 108 and 109 remain whichcontain no stop-weld pattern.

The pattern of stop-weld material may be provided by numerous methodsknown to those skilled in the art. For example, the well-known silkscreen process may be utilized. Likewise, the process covered in Keithapplication, Ser. No. 723,055 may be utilized in which a stop-weldpattern is applied over the entire first sheet and then a portion isremoved, for example, by milling, to define those portions where bondingis to take place.

Thus, when the second sheet is placed upon the sheet and the sheets arebonded together by appropriate steps, bonding will take place only inthe portions 108 and 109. This bonding may be either cold bonding or hotbonding as described in Ser. No. 630,376 now abandoned and in Ser. No.723,055.

After the bonding operation, the strip 1 is cut into a plurality ofsections 2, 3, 4, 5, etc. The inward length of the cut in FIG. 2 is madeto include the nonbonded edge portions. It will be apparent from FIG. 3that for each of the cut elements, 2 and 3 in FIG. 2, two opposite finsfrom each result, or a total of four.

The strip may be inflated either before or'after the fins are bent andtwisted. In any case, a center passageway 6 is provided which may haveenlarged openings 7 and 8 at the ends thereof, provided by way of astop-weld pattern and after inflation, inlet and outlet conduitpassageways will result.

After the cutting operation, the sections 2 and 3 are bent. As mentionedpreviously, this bending involves separating the two sheets and bendingthem approximately 180 with respect to each other and approximately 90with respect to a plane passing through the bonded portions. The sheetsare also twisted 90. While separate operations may be provided for thebending and twisting, in the preferred embodiment of the presentinvention, the bending and twisting is done simultaneously.

If the heat exchanger has not yet been inflated, the next step of theprocess is to inflate it to define the passageway 20. An inflationneedle and fluid pressure is all that is necessary for the inflationoperation, as is now well known in the art.

The heat exchanger can then be bent into various appropriate shapes.

According to one embodiment of the present invention, the 7 heatexchanger may be bent into a helix, as shown in FIGS. 4 and 5. Thus, theheat exchanger shown in FIG. 4 has a center conduit 220 through which aheat exchange medium is passed. Bonded areas 230 and 231 are provided.Integral therewith, bent and twisted fins 241, 242, 243 and 244(indicated schematically) are provided, as described in regard to FIG.3. The top of the helix is shown in FIG. 5, and an end portion 270 isprovided similar to that in FIG. 3. However, it is apparent that at onepoint thereof, 250, the heat exchanger moves downwardly and another bendportion 280 is encountered. Another bend portion 290 would be found atthe opposite end and so forth. It will be apparent that a heat exchangerof this type will occupy very little space as far as the verticaldimension is concerned. Each layer will occupy no more height than thecombined height of the passageway 220 and bonded portions 230 and 231.Thus, no additional volume is occupied by fins. Connections of anappropriate nature are provided at either end of the heat exchanger forthe passage of a fluid, generally a liquid cooling medium, throughconduit portion 220.

Another embodiment of the present invention is shown in FIGS. 6 and 7.In this case, the heat exchanger having a center conduit 320 is woundinto a serpentine shape having legs 301, 302 and 303. This results inend portions 370. As indicated schematically, there is provided, asdescribed previously, fins 341, 342, 343 and 344. If desired, a secondrow may be provided. Ifa second row is provided, as shown in FIG. 7, theleg 304 moves downwardly and then the heat exchanger is wound again in aserpentine manner. Thus, end 37E, shown in FIG. 6 is the end portion ofthe second tier. Likewise, end portion 372 is from the second tier. Thistwo-tiered serpentine structure again is effective in keeping the volumerequired to house the heat exchanger at a minimum. Furthermore, by usingtwo tiers, there is a high concentration of fins, so that'effective heatexchange is obtained between a fluid passing through the fins and acooling medium passing through passageway 320.

Other geometrical shapes which take advantage of the dimensionalreduction provided by the present invention will be apparent to thoseskilled in the art. For example, the additional shapes shown in FIG.9-l3 of Ser. No. 630,376 now abandoned, may be utilized, as well as manyothers.

It is to be understood that the invention is not limited to-theillustrations described and shown herein which are deemed to be merelyillustrative of the best modes of carrying out the invention, and whichare susceptible of modifications of form, size, arrangement of parts,and detail of operation, but rather is intended to encompass all suchmodifications which are within the spirit and scope of the invention asset forth in the appended claims.

lclaim: I

1. A heat exchanger comprising: two sheets of metal, each of whichcooperate to completely define at least one tubular passageway; edgeportions defined by the same two sheets of metal which define saidtubular passageway, said edge portions being on opposite sides of saidtubular passageway and being separated from said tubular passageway by abonded portion extending coextensively with said edge portions and saidtubular assageway in which said sheets of metalare bonded toget er; saidsheets in each of said edge portions being bent apart greater than withrespect to each other to provide efficient heat exchange surface; saidbent apart sheets in said edge portion being formed into fins, said finsbeing transverse to the longitudinal axis of said heat exchanger, saidfins being twisted approximately 90 and being parallel throughout atleast a substantial portion of said heat exchanger; whereby said finsare in heat exchange relationship with said tubular passageway, the heatexchange between said tubular passageway and said fins taking placesubstantially through the said two sheets of metal which define saidtubular passageway.

2. A heat exchanger according to claim l in which planes passing throughsaid fins define acute angles at outer bend portions of said heatexchanger.

3. A heat exchanger according to claim l in which at the inner edge bendportions, said fins point toward each other.

4. A heat exchanger according to claim 1 which is wound into a helix.

5. A heat exchanger according to claim 1 which is wound into aserpentine.

6. A heat exchanger comprising two sheets of metal, each of whichcooperate to completely define at least one tubular passageway; edgeportions defined by the same two sheets of metal which define saidtubular passageway, said edge portions being on opposite sides of saidtubular passageway and being separated from said tubular passageway by abonded portion extending coextensively with said edge portions and saidtubular passageway in which said sheets of metal are bonded together;said sheets in each of said edge portions being bent apart at leastabout with respect to each other to provide efficient hcat exchangesurface; said bent apart sheets in said edge portions .being formed intofins, said fins being transverse to the longitudinal axis of said heatexchanger; said fins being twisted approximately 90 and said fins beingparallel throughout at least a substantial portion of said heatexchanger; said heat exchanger being wound into a serpentine structurecomprising a first row having a serpentine configuration and at least anadjacent second row having a serpentine configuration, wherein saidfirst and said at least second row are integrally connected, whereby thefins are in heat exchange relation with said tubular passageway, theheat exchange between said tubular passageway andsaid fins taking placesubstantially through the said two sheets of metal which define saidtubular passageway.

